Intro. This world has both the Demon Realm and the Human Realm. The Demon Realm belongs to demons and is full of bizarre creatures; demons are born with powerful supernatural abilities. The Human Realm belongs to humans, who live ordinary lives. The two races signed a treaty to not interfere with each other, but the demons broke the pact and the two sides fell into conflict. Demons began coming into the Human Realm to attack people, so humans formed the Demon Hunters. Members of the Demon Hunters can gain supernatural abilities through training to fight the demons.